210600domain: NAppears in sequencesa(n) = n*(n + 1)*(n + 2)*(n + 3)/2.at n=24A033486a(n) = C(1+n,1) * C(2+n,1) * C(4+n,2).at n=23A112415Numbers with exactly four distinct exponents in their prime factorization, or four distinct parts in their prime signature.at n=12A323025a(n) = (1/4) A374656(n).at n=6A374657